March'09

Propagation Forecast

During the second half of February, conditions have remained much the same with the A index at 5 and the K index at 2. This is set to continue into March, except for the 13th , when the A index will peak at 12 and the K index will reach 4. The 14th March will be much the same with the A index down to 10 and the K down to 3. Conditions will settle beck to ‘normal’ by the 15th with the A and K indices returning to 5 and 2 respectively. The Solar flux, however is forecast to stay at a steady 70 throughout this period.
(Data from: http://www.wm7d.net/hamradio/solar/27d_forecast.shtml )

Solar Cycle 24 Update
Looking at the Sunspot trend charts on Solarcycle24.com, it seems we will not see any significant difference in HF conditions until early 2010 when sunspot activity is forecast to rise steadily until the end of 2012. This will steadily drop down towards another low period by around 2020. Detailed charts can be found at: http://solarcycle24.com/flares.htm

Online Popagation Primer
Here is an interesting website featuring Flash Media videos about how HF propagation works, which is divided into sections including The Sun, The Ionosphere and the indices, explaining how to understand the A index, the K index and the Solar Flux. You will require a Broadband connection to view these files
http://www.ae4rv.com/tn/propflash.htm See also this website explaining how shortwave propagation actually works: http://dzabcik.home.texas.net/propagation.html See also Propagation Noise and Effectiveness at: http://hfradio.org/ace-hf/ace-hf-noise.html

AM Noise Sources“The radio noise problem is as old as radio itself. Unfortunately it is getting worse as technology steadily progresses and more man-made electronic products hit the shelves. This is a direct result of mainly consumer products that generate an increasingly higher noise level. The technology behind the AM broadcast signal is very out-dated as far as current technology is concerned, not to mention that the AM broadcast band is located in the very vulnerable medium wave frequency band.”
This is an article from radiolabs.com which details the amount of devices which can cause noise on the AM bands. This article can be found at: http://www.radiolabs.com/Articles/amnoise.html

Localised Radio Interference
The number of videos on YouTube showing the interference that 'Homeplug' type devices cause to peoples' enjoyment of radio listening continues to grow. A selection of Youtube postings can be found at: http://www.southgatearc.org/news/february2009/new_plt_interference_videos.htm

There is also the UKQRM group at: http://www.ukqrm.org/ There are many features on this site including a page for identifying different sources of interference from power line adapters to electric fences: http://www.mikeandsniffy.co.uk/UKQRM/database.htm For the latest updates, you can also join their Yahoo Group at: http://tech.groups.yahoo.com/group/UKQRM/
(From Mike Terry 9 February 2009)

Links to these articles and more can be found at: http://www.jameswelsh.org.uk